I got a new Chevy 2500HD 4x4 gas engine. It calls for 60psi front and 80 psi rear. I was told I can not run lower pressure. The truck is run for hunting and to go to and from work. It is unloaded. It has E tires. Any one with a good unloaded pressure? Also how can the tire pressure monitor be reset? The dealer said it can not be reset. OnStar sent me a report that they were low now.